Kathy Evingson tries to ride her bike through the deep snow during the Little-Su 50K at Point Mackenzie near Knik, Alaska on Sunday Feb. 17, 2008. The 31-mile trek across frozen rivers and snowy swamps, open to skiers, snowshoers and runners, it is often won by competitors using bicycles. (AP Photo/Robert DeBerry )

Dave Byers biking with his dog Kenai along a trail with the Tetons in the background in Jackson, WY. The number of snow bike devotees has been steadily growing since the introduction of fat-tire bikes. Undated. (AP Photo/Scott Fitzgerald )

Photo: Scott Fitzgerald, San Francisco Chronicle

Dave Byers biking with his dog Kenai along a trail with the Tetons...

Dave Byers biking with his dog Kenai along a trail with the Tetons... Photo-5782779.78546 - SFGate

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Michael Pach of South Boston heads home on a bicycle over the old Northern Avenue bridge in Boston, Friday, Feb. 7, 2003, as a winter storm dumped several inches of snow throughout the Northeast. (AP Photo/Julia Malakie)

Photo: JULIA MALAKIE, San Francisco Chronicle

Michael Pach of South Boston heads home on a bicycle over the old...

Michael Pach of South Boston heads home on a bicycle over the old... Photo-5782782.78546 - SFGate

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A man rides his bicycle along a snow-covered street on January 2, 2014 in the Brooklyn borough of New York City. (Photo by Spencer Platt/Getty Images)

Photo: Spencer Platt, San Francisco Chronicle

A man rides his bicycle along a snow-covered street on January 2,...

A man rides his bicycle along a snow-covered street on January 2,... Photo-5782761.78546 - SFGate

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A man walks his bicycle in serpentine fashion along a snow-covered street on January 2, 2014 in the Brooklyn borough of New York City. (Photo by Spencer Platt/Getty Images)

Photo: Spencer Platt, San Francisco Chronicle

A man walks his bicycle in serpentine fashion along a snow-covered...

A man walks his bicycle in serpentine fashion along a snow-covered... Photo-5782774.78546 - SFGate

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A resident pushes his bicycle along a snow-covered road in Kabul on December 30, 2013. About two inches of snow fell overnight in Kabul marking the winter season's first snowfall in the city. AFP PHOTO/Roberto SCHMIDTROBERTO SCHMIDT/AFP/Getty Images

Photo: ROBERTO SCHMIDT, San Francisco Chronicle

A resident pushes his bicycle along a snow-covered road in Kabul on...

A resident pushes his bicycle along a snow-covered road in Kabul on... Photo-5782775.78546 - SFGate

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NEW YORK, NY - JANUARY 03: A man rides a bicycle through a cold and snow covered Manhattan following a snow storm that left up to 8 inches of snow on January 3, 2014 in New York, United States. The major winter snowstorm, which forced New York City public schools to close and shut down the Long Island Expressway, was viewed as a test for the new mayor of New York City, Bill de Blasio. (Photo by Spencer Platt/Getty Images)

Photo: Spencer Platt, San Francisco Chronicle

NEW YORK, NY - JANUARY 03: A man rides a bicycle through a cold...

NEW YORK, NY - JANUARY 03: A man rides a bicycle through a cold... Photo-5782765.78546 - SFGate

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A bicycle is buried by overnight snowfall, Friday, Jan. 3, 2014, in the Queens borough of New York. New York City public schools were closed Friday after up to 7 inches of snow fell by morning in the first snowstorm of the winter. (AP Photo/John Minchillo)

Don Hiles rides his bicycle to work through the fresh snow and a cold wind in Champaign, Ill., on Tuesday Jan. 21, 2014. Hiles said he tries to ride his bike to and from work every day. "I had to walk one day so far this year", said Hiles. A storm that pushed through the region forced school cancellations and made commutes treacherous throughout Illinois. (AP Photo/News-Gazette, John Dixon)

Photo: John Dixon, San Francisco Chronicle

Don Hiles rides his bicycle to work through the fresh snow and a...

Don Hiles rides his bicycle to work through the fresh snow and a... Photo-5782756.78546 - SFGate

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A pedestrian pushes his bicycle through a snow storm, Tuesday, Jan. 21, 2014, in south Philadelphia. (AP Photo/Matt Slocum)

Photo: Matt Slocum, San Francisco Chronicle

A pedestrian pushes his bicycle through a snow storm, Tuesday, Jan....

A man walks past a snow encrusted bicycle with wind chills nearing minus 30 Fahrenheit on Tuesday, Jan. 7, 2014, in downtown Chicago. Dangerously cold polar air snapped decades-old records as it spread Tuesday from the Midwest to southern and eastern parts of the U.S. and eastern Canada, making it hazardous to venture outside and keeping many schools and businesses closed. (AP Photo/Andrew A. Nelles)

NEW YORK, NY - JANUARY 03: People ride bicycles down Smith Street after winter storm 'Hercules' on January 3, 2014 in the Brooklyn borough of New York City. The major winter snowstorm, which forced New York City public schools to close and shut down the Long Island Expressway, was being viewed as a test for the new mayor of New York City Bill de Blasio. (Photo by Michael Heiman/Getty Images)

NEW YORK, NY - JANUARY 03: A man rides a bicycle through a cold and snow covered Manhattan following a snow storm that left up to eight inches of snow on January 3, 2014 in New York City. (Photo by Spencer Platt/Getty Images)

Photo: Spencer Platt, San Francisco Chronicle

NEW YORK, NY - JANUARY 03: A man rides a bicycle through a cold...

NEW YORK, NY - JANUARY 03: A man rides a bicycle through a cold... Photo-5782760.78546 - SFGate

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Share bicycles stand during a snow storm in New York, January 21, 2014. In New York, a storm alert was issue for noon (1700 GMT) Tuesday to 6:00 am (1100 GMT) Wednesday with as much as a foot (30 centimeters) forecast for the metropolitan region. AFP PHOTO/Emmanuel DunandEMMANUEL DUNAND/AFP/Getty Images

Photo: EMMANUEL DUNAND, San Francisco Chronicle

Share bicycles stand during a snow storm in New York, January 21,...

Share bicycles stand during a snow storm in New York, January 21,... Photo-5782751.78546 - SFGate

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NEW YORK, NY - JANUARY 21: A man rides a bicycle in Manhattan during a snowstorm that is moving through the Northeast on January 21, 2014 in New York City. (Photo by Spencer Platt/Getty Images)

Photo: Spencer Platt, San Francisco Chronicle

NEW YORK, NY - JANUARY 21: A man rides a bicycle in Manhattan...

NEW YORK, NY - JANUARY 21: A man rides a bicycle in Manhattan... Photo-5782752.78546 - SFGate

A man uses plastic bags to cover his hands while riding a bicycle... Photo-5782753.78546 - SFGate

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A man rides a bicycle through the snow on North Potomac Street in Hagerstown, Md., Tuesday, Jan. 21, 2014. Four-wheeled vehicles across the region had a slippery commute. (AP Photo/The Herald-Mail, Kevin G. Gilbert)

Photo: Kevin G. Gilbert, San Francisco Chronicle

A man rides a bicycle through the snow on North Potomac Street in...

A man rides a bicycle through the snow on North Potomac Street in... Photo-5782750.78546 - SFGate

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Delivery bicycles covered in snow on Manhattan's east side February 26, 2010 (Stan Honda/AFP/Getty Images)

Photo: Stan Honda, AFP/Getty Images

Delivery bicycles covered in snow on Manhattan's east side February...

A person rides a bicycle across Broad Street in view of City Hall during a winter snow storm in Philadelphia, Friday, Feb. 26, 2010.

Photo: Matt Rourke, AP

A person rides a bicycle across Broad Street in view of City Hall...

A person rides a bicycle across Broad Street in view of City Hall... Photo-2031356.78546 - SFGate

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Snowed covered bicycles are seen in Munich, southern Germany, on Monday, Dec. 21st. Snowstorms and subfreezing temperatures have battered Europe, killing 29 people in Poland alone and wreaking havoc on air, train and car travelers from the Nordics to Italy on the last weekend before Christmas.

Residents of Copenhagen, Denmark trudge through the snow Monday Feb. 6, 2006. Heavy snow blanketed much of Denmark on Monday. Heavy snows generally do not prevent Danes from going to and from work on their bicycles. (AP Photo/John McConnico)

In this photo taken Monday, Jan. 4, 2010, a child flies a kite at a snow-covered bicycles parking place in Beijing. Some Chinese factories were ordered Tuesday, Jan. 5, 2010 to shut down to ensure sufficient power to heat homes as demand surged amid record-setting winter cold, a utility company said. A weekend storm blanketed much of China with snow, sending temperatures plunging, snarling traffic and prompting some cities to close schools.

Photo: AP

In this photo taken Monday, Jan. 4, 2010, a child flies a kite at a...

In this photo taken Monday, Jan. 4, 2010, a child flies a kite at a... Photo-2033549.78546 - SFGate

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Bicycles are covered in ice Tuesday Dec. 11, 2007 at Truman State University in Kirksville, Mo. after an overnight ice storm. (AP Photo/ Al Maglio)
Ran on: 12-12-2007
An overnight storm left these bikes covered with ice Tuesday at Truman State University in Kirksville, Mo. The storm cut power to a million utility customers in much of Kansas, Missouri, Illinois and Iowa. The storm has been blamed for at least 24 deaths since it developed last weekend. Downed power lines caused dozens of fires in Oklahoma. Utilities said electricity may not be restored for days, if not weeks. Officials in Missouri, Kansas and Oklahoma declared states of emergency.

A bicyclist pedals across the Stone Arch Bridge in Minneapolis, Thursday evening, Dec. 8, 2005. Bicyclers are an amazingly common, if still startling, sight on Twin Cities streets even on the most frigid days. (AP Photo/Ann Heisenfelt)

Photo: ANN HEISENFELT, San Francisco Chronicle

A bicyclist pedals across the Stone Arch Bridge in Minneapolis,...

A bicyclist pedals across the Stone Arch Bridge in Minneapolis,... Photo-5783445.78546 - SFGate

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TRAVEL TROMSO E -- A man rides a bicycle through the snowy streets of Tromsoe, Norway Nov. 15, 2006. Despite the Arctic climate, the town's people are known for their boisterous spirits.